<template>
	<div class="play">
		<!-- 模糊背景(靠样式设置), 固定定位 -->
		<div class="song-bg" :style="`background-image: url(${
        songInfo && songInfo.al && songInfo.al.picUrl
      }?imageView&thumbnail=360y360&quality=75&tostatic=0);`"></div>
		<!-- 播放页头部导航 -->
		<div class="header">
			<van-icon name="arrow-left" size="20" class="left-incon" @click="$router.back()" />
		</div>
		<!-- 留声机 - 容器 -->
		<div class="song-wrapper">
			<!-- 留声机本身(靠css动画做旋转) -->
			<div class="song-turn ani" :style="`animation-play-state:${playState ? 'running' : 'paused'}`">
				<div class="song-img">
					<!-- &&写法是为了防止报错, 有字段再继续往下访问属性 -->
					<img style="width: 100%" :src="`${
              songInfo && songInfo.al && songInfo.al.picUrl
            }?imageView&thumbnail=360y360&quality=75&tostatic=0`" alt="" />
				</div>
			</div>
			<!-- 播放按钮 -->
			<div class="start-box" @click="audioStart">
				<span class="song-start" v-show="!playState"></span>
			</div>
			<!-- 播放歌词容器 -->
			<div class="song-msg">
				<!-- 歌曲名 -->
				<h2 class="m-song-h2">
					<span class="m-song-sname">{{ songInfo.name }}-{{
              songInfo && songInfo.ar && songInfo.ar[0].name
            }}</span>
				</h2>
				<!-- 歌词部分-随着时间切换展示一句歌词 -->
				<div class="lrcContent">
					<p class="lrc">{{ curLyric }}</p>
				</div>
			</div>
			<!-- 留声机 - 唱臂 -->
			<div class="needle" :style="`transform: rotate(${needleDeg});`"></div>
		</div>
		<!-- 播放音乐真正的标签
      看接口文档: 音乐地址需要带id去获取(但是有的歌曲可能404)
      https://binaryify.github.io/NeteaseCloudMusicApi/#/?id=%e8%8e%b7%e5%8f%96%e9%9f%b3%e4%b9%90-url
     -->
		<audio ref="audio" preload="true" :src="`https://music.163.com/song/media/outer/url?id=${id}.mp3`"></audio>
	</div>
</template>

<script>
	// 获取歌曲详情和 歌曲的歌词接口
	// import { getSongByIdAPI, getLyricByIdAPI } from '@/api'

	import {
		Icon
	} from 'vant'

	export default {
		components: {
			[Icon.name]: Icon,
		},
		name: 'play',
		data() {
			return {
				playState: false, // 音乐播放状态(true暂停, false播放)
				id: this.$route.query.id, // 上一页传过来的音乐id
				songInfo: {}, // 歌曲信息
				lyric: {}, // 歌词枚举对象(需要在js拿到歌词写代码处理后, 按照格式保存到这个对象)
				curLyric: '', // 当前显示哪句歌词
				lastLy: '' // 记录当前播放歌词
			}
		},
		computed: {
			needleDeg() { // 留声机-唱臂的位置属性
				return this.playState ? '-7deg' : '-38deg'
			}
		},
		methods: {
			async getSong() { // 获取歌曲详情, 和歌词方法
				const res = await getSongByIdAPI(this.id)
				this.songInfo = res.data.songs[0]
				// 获取-并调用_formatLyr方法, 处理歌词
				const lyrContent = await getLyricByIdAPI(this.id)
				const lyricStr = lyrContent.data.lrc.lyric
				this.lyric = this._formatLyr(lyricStr)
				// 初始化完毕先显示零秒歌词
				this.curLyric = this.lyric[0]
			},
			_formatLyr(lyricStr) {
				// 可以看network观察歌词数据是一个大字符串, 进行拆分.
				let reg = /\[.+?\]/g // 
				let timeArr = lyricStr.match(reg) // 匹配所有[]字符串以及里面的一切内容, 返回数组
				console.log(timeArr); // ["[00:00.000]", "[00:01.000]", ......]
				let contentArr = lyricStr.split(/\[.+?\]/).slice(1) // 按照[]拆分歌词字符串, 返回一个数组(下标为0位置元素不要,后面的留下所以截取)
				console.log(contentArr);
				let lyricObj = {} // 保存歌词的对象, key是秒, value是显示的歌词
				timeArr.forEach((item, index) => {
					// 拆分[00:00.000]这个格式字符串, 把分钟数字取出, 转换成秒
					let ms = item.split(':')[0].split('')[2] * 60
					// 拆分[00:00.000]这个格式字符串, 把十位的秒拿出来, 如果是0, 去拿下一位数字, 否则直接用2位的值
					let ss = item.split(':')[1].split('.')[0].split('')[0] === '0' ? item.split(':')[1].split('.')[
						0].split('')[1] : item.split(':')[1].split('.')[0]
					// 秒数作为key, 对应歌词作为value
					lyricObj[ms + Number(ss)] = contentArr[index]
				})
				// 返回得到的歌词对象(可以打印看看)
				console.log(lyricObj);
				return lyricObj
			},
			audioStart() { // 播放按钮 - 点击事件
				if (!this.playState) { // 如果状态为false
					this.$refs.audio.play() // 调用audio标签的内置方法play可以继续播放声音
				} else {
					this.$refs.audio.pause() // 暂停audio的播放
				}
				this.playState = !this.playState // 点击设置对立状态
			},
			showLyric() {
				// 监听播放audio进度, 切换歌词显示
				this.$refs.audio.addEventListener('timeupdate', () => {
					let curTime = Math.floor(this.$refs.audio.currentTime)
					// 避免空白出现
					if (this.lyric[curTime]) {
						this.curLyric = this.lyric[curTime]
						this.lastLy = this.curLyric
					} else {
						this.curLyric = this.lastLy
					}
				})
			}
		},
		mounted() {
			this.getSong()
			this.showLyric()
			console.log(this.$route.query.id);
		}
	}
</script>

<style scoped>
	.header {
		height: 50px;
	}

	.play {
		position: fixed;
		top: 0;
		left: 0;
		right: 0;
		bottom: 0;
		z-index: 1000;
	}

	.song-bg {
		background-color: #161824;
		background-position: 50%;
		background-repeat: no-repeat;
		background-size: auto 100%;
		transform: scale(1.5);
		transform-origin: center;
		position: fixed;
		left: 0;
		right: 0;
		top: 0;
		height: 100%;
		overflow: hidden;
		z-index: 1;
		opacity: 1;
		filter: blur(25px);
		/*模糊背景 */
	}

	.song-bg::before {
		/*纯白色的图片做背景, 歌词白色看不到了, 在背景前加入一个黑色半透明蒙层解决 */
		content: " ";
		background: rgba(0, 0, 0, 0.5);
		position: absolute;
		left: 0;
		top: 0;
		right: 0;
		bottom: 0;
	}

	.song-wrapper {
		position: fixed;
		width: 247px;
		height: 247px;
		left: 50%;
		top: 50px;
		transform: translateX(-50%);
		z-index: 10001;
	}

	.song-turn {
		width: 100%;
		height: 100%;
		background: url("./img/bg.png") no-repeat;
		background-size: 100%;
	}

	.start-box {
		position: absolute;
		width: 156px;
		height: 156px;
		position: absolute;
		left: 50%;
		top: 50%;
		transform: translate(-50%, -50%);
		display: flex;
		justify-content: center;
		align-items: center;
	}

	.song-start {
		width: 56px;
		height: 56px;
		background: url("./img/start.png");
		background-size: 100%;
	}

	.needle {
		position: absolute;
		transform-origin: left top;
		background: url("./img/needle-ab.png") no-repeat;
		background-size: contain;
		width: 73px;
		height: 118px;
		top: -40px;
		left: 112px;
		transition: all 0.6s;
	}

	.song-img {
		width: 154px;
		height: 154px;
		position: absolute;
		left: 50%;
		top: 50%;
		overflow: hidden;
		border-radius: 50%;
		transform: translate(-50%, -50%);
	}

	.m-song-h2 {
		margin-top: 20px;
		text-align: center;
		font-size: 18px;
		color: #fefefe;
		overflow: hidden;
		white-space: nowrap;
		text-overflow: ellipsis;
	}

	.lrcContent {
		margin-top: 50px;
	}

	.lrc {
		font-size: 14px;
		color: #fff;
		text-align: center;
	}

	.left-incon {
		position: absolute;
		top: 10px;
		left: 10px;
		font-size: 24px;
		z-index: 10001;
		color: #fff;
	}

	.ani {
		animation: turn 5s linear infinite;
	}

	@keyframes turn {
		0% {
			-webkit-transform: rotate(0deg);
		}

		100% {
			-webkit-transform: rotate(360deg);
		}
	}
</style>
